Unloader for fluid-compressors.



W. PRELLWITZ.

UNLOADER FOR FLUID OOMPRESSORS.

APPLIOATION FILED MAY31, 1907.

Patented Mar. 5, 1912.

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Patented Mar 5, 1912 a SHEETS l Q w JM S IIA; m M. b/ H w 2 m s 9 m] V In" m n W n M w :WU Z 3 N z I! m i W i mm m -l m m m I W Wm M F H V E O. D I e 5 m m w N A U m E 0 L W. PRELLWITZ. UNLOADER FOR FLUID GOMPRESSORS. APPLICATION FILED MAY 31, 1907;

1,019,359: Patented Mar.5,1912.

5 SHEETS-SHEET 3.

W. PRELLWITZ.

UNLOADER FOB. FLUID GOMPRESSORS.

APPLICATION FILED MAY 31, 1907.

Patented Mar. 5, 1912.

6 SHEETS-SHEET 4.

I2 2*6/4227 3 a yaw M W. PRBLLWITZ.

UNLOADER FOR FLUID OOMPRESSORS.

APPLICATION FILED MAY 31, 1907. 1,01 9,359, Patented Mar. 5, 1912.

5 SHEETS-SHEET 6.

' unload the compressorrlses to a predetermined point and load the to predetermined points,

UNITED STATES PATENT OFFICE:

PENNSYLVANIA, ASSIGNOR TO INGERSOIiL-BAND WILLIAM PREILWITZ, 0F EASTON,

COMPANY, OF NEW YORK, N. Y., A CORPOBATION'OF NEW JERSEY;

UNLOADEB FOB FLUID-COMPRESSORS.

Specification of Letters Patent. I Application filed May 31, 1907. Serial No. 376,702,

To all 'whom it may concern:

and State of Pennsylvania, have invented a new and useful Improvement in Unloaders for Fluid-Compressors, of which the following is a specification,

My invention relates to means-for unloading fluid compressors and consists broadly innovel means arranged to automatically when the pressure compressor when the pressure falls to a r'edetermined point, said means comprismg an auxiliary receiver, a valve for. opening and closing communication between the compressor and auxiliary receiver and a regulating device, such as a fluid ressure governed 'regulator,'connected to t e back of the auxiliary receiver valve.

My invention further consists in means for unloading and loading the compressor step by step as the pressure risesand falls said means com-- prising a plurality of auxiliary receivers, valves arranged to open and close communication between the compressor and the auxiliary receivers and a plurality of regulating devices, suchas fluid pressure governed regulators, connected to the backs of the auxiliary receiver valves for unloading the valves successively as difierent high pressures are reached.-

The present invention is also directed to the novel means above set forth, applied to 'the cylinder or duplex cylinder of a singlestalge fluid compressor.

ractical embodiments of my' invention are represented in the accompanying drawin? in which igure 1 represents an end view of a one cylinder single stage fluid compressor with m novel unloading means applied thereto,

Fig. 2 is a top plan view of the same, Fig. 3 1s a side view partially -in longitudinal central section, Fig. 4 is a central vertical section through the fluid pressure governed regulator which is used irr connection with my unloading means, Fig. 5 represents a central vertical section of the regulating valve, Fig. 6 is a view taken in the plane of the line A--A of Fig. 4, look A: in the disure governed regulators of rection of the arrows, Fig.7 is a horizontal section taken in the plane of the line B-B- of Figs. 4, 5, 6. Figs. 8, 9, 10, 11, 12 are diagrammatic plan views showing different arrangements of the unloading .means as applied to single stage duplex fluid compressors, and Fig. 13 is a diagrammatic plan view showing another arrangement of the unloading means as applied to .a one cylinder [single stage compressor.

Proceeding to describe 'the form shown in Figs. 1 to 7 inclusive; the cylinder of'the piston inlet-fluid compressor shown herein is denoted by 1, the piston by 2, its inlet by 3 and its rod through which theiston d erives its motion, by 4. It is to e understood that this piston is driven from any suitable source ofpower, not shown herein.

The main discharge by 5, the air passages by 6 and the pipe leading to the receiver by 7, one or moreauxiliary receivers .8 are provided which arearran ed to be opened and closed to the interior 0 the cylinder'by one or more auxiliar valves 9. In the present instance four of t ese receivers are shown, two being shown in communication with one end of the cylinder and two being shown in communication with the other end of the cylinder. The backs of the auxiliary receiver valves 9 are brought into communication with regulating devices, such as fluid presthe form disclosed'in United States Letters Patent No. 514=,-839 dated February 13, 1894, a general description of the construction, arrangement' and operation ofwhich follows.

10 is a cylindrical valve box containing the main slide valve 11 having piston heads 12, 13 and a bridge port $1.. This valve box is provided with a port 14: open to at-- mosphere and a port 15 which is in communication with the backs of the two auxiliary receiver valves 9 at opposite ends of the cylinder 1 throu h a pipe 16. The main valve 11 is operated y pressure upon one or the other of its piston heads 12, 13, by fluid lat'evtezlzMzng: 5; 1915;

valves are denoted o trolling the vii 60 receivers izpon opposite ends of each of the:

i that any number of auxiliary-receivers may the receiver to the space between the main.

valve piston heads 12, 13 so that this space and the interior of the box 20-,are always open to receiver pressure. On the top of the 5 auxiliary valve box 20 is acyli'nder 24, whichis open at the-bottom to the interior of the; said box. A, piston25 is .fitted to slide in the cylinder 24:, which piston is arranged to move the auxiliary valve 19 under the i uencel of receiver pressure. This auxiliary valvf e 19 'is provided with app and lower bridge ports 26, 27,. and uppe and lower thrl ugh ports 28, 29. The

. .main }valve box 10 1; ,provided with a port, 30 intermediate vthe' wports 17, 18. Theseseverall: ports aretso arranged that the movement of theadxiliary valve will, cont-rol the movementf- -of the main. valve for opening the pressure from the receiver to 20 the backs of the-auxiliary receiver valves 9 through port #5, and pipe 16, when the main valve is in'- one position or openf-the backs of the said auxiliary receiver val es to atmosphere through pipe 16, port/15, bridge port 11* and port 14, when the'main' valve is in its gther, position. The. piston 25 for operatin the auxiliary valve '19 of the regulator is weighted to hold-the auxiliary valve in position to keep-the load on $9 the auxiliary jreceiver valve .until a prede termined high pressure has beenjreached, means of a weighted arm.31, the-weights @32 on which may be so regulated that the backs of the auxiliary receiver valves 9 will 5 the unloaded by the movement of" the main valve under the control of the movement of 'tthe auxiliary valve when said. predeter f-ininedj hig'h pressure-has been reached. I ,w In the form shown in Fig. 13, each of 4'0. the,fou r auxiliary receivers is provided with Ca fluid pressure governed regulator. ,Iii-

'/I\ig'. 9 a single stage duplex fluid compres- 's'qr 'is"shown in' which each cylindengi'sl shown as being provided withtwo auxiliary a receivers ateac li end and a fluid pressure- 1 govierned negulator is provided for the valve ofg eachauxiliary receiver. -InFig.-;10 four 5- fiufid .pre'ssnre/ ,l ovei'ned regulators are shown, eaclx'Tegiilator beingshownas co'nyes of two auxiliary rcceiv-, ers'oncorresponding-ends of the' two cylinders. Flg. 11 iour'fluid pressure govern d regulators 'are stipwn, each regulator beigiig arranged to control the operation of '55 the 'valves ,o lit$vo auxiliary receiifersupon opposite ends of the two cylinders. -In. 1?i v12 two fluid pressure governed regulators, are shown, each'being arrangedjto controllthe operation of the valves of two auxiliary two cylihdei's. The several terms; shown. are for the purpose-oi illustrating the point be employed and any number of regulating devices, such as fluid pressure governed :terior of the compressor cylinder. the compressor starts, the pressure is raised [auxiliary receiver.

for each auxiliary receiver.

regulators may be employed to suit different requirements.

The operation of the simplest toi-in of my invention would. be as follows. An-a uxil- 1ary recelver of a predetermined size 1s connected to the compressor and a valve isprovlded for opening and closing commu-= receiver and the in- When nication between sai in the auxiliary receiver corresponding to the rise of pressure in the system. After the pressure has been raised to its regular working condition, the auxiliary receiver valve tends to remain closed because of the pressure from the receiver on theback of the valve. When the pressureflhas been raised to a predetermined high point, the regulator which is controlledby receiver pressure will automatically unload the back of the auxiliary receiver valve, thusallowing the fluid under pressure to be forced from" the cylinder into the auxiliary receiver on the forward stroke of the piston and to pass back. from the auxiliary receiver into the cylinder on the return stroke of thep1ston,'the unloaded valve remaining open so long as the power of the valve spring, which, is made very light, is less than thepressure on the valve of the fluid within the cylinder, thus automatically reducing-the power of the compressor to a predetermined extent fixed by the relative capacities of the compressor cylinder and As the fluid pressure falls in the receiver, the regulator will automatically load the auxiliary receiver valve by opening the backof the same to receiver pressure,=thus closing the valve and permitting-thei'compressor to again operate under :"ifull load.

Itis obvious that by varying the size of the auxiliary receiver, the compressor can be entirely unloaded or only partially unloaded, depending upon the capacity of the auxiliary. receiver. An auxiliary receiver may be connected to both ends of the cylinder and-a single regulating device,'such as a fluid pressure governed regulator, may be provided for the valves on both auxiliary receivers, or,./a regulator may be provided ,If it is desired to unload the compressor step, by step',"an additional set of auxil ary receivers may be providedffor the ends of the cylinder, the valves btthe said addi- -.-it onal set of auxiliary receivers being controlled by a second, regulating device, such ts/thefluid pressure governed regulator .above' describdfwhich is set by means of itsfiweight-sltbj further unload the compressor after-the first set of auxiliary receivers have been used for partially unloading the compressor. If it is desired. to unload the compressor in four steps, as for '--,in.stance in the form-shown in Fig. 13, one i-- way of acc0m lishing this result would be to first unload. the auxiliary receiver valve at the'front end of the cylinder, then ungload fthe auxiliary receiver valve at the {ybaclrendg then unload the other auxiliary .receiver valve at the front end, and finally .ifunload the other auxiliary receiver valve at jthe back end. It will also be seen that as 1 the gfluid ressure falls; in the receiver the load-will e automatically thrown on to the compressor step by step, this radual increase in the load being a valua le feature of my invention, especially when used in l .15 connection with large machines. l It is obvious that by making different "combinations of auxiliary receivers and regl iilators, the unloading of the compressor camp: accomplished either atone time or in succ si've steps as the fluid ,in the receiver reaches difi'erent'predetermined high pressures. 1

When the auxiliary receiver valves are unloaded they will stay open as long as the fluid pressure on the valves over-balances the 'ower of the valve springs and therefore the amount o f-work required for filling the auxiliary receiverswill be again given back to themachine on-the return 80" stroke as the volume of fluid is expanded. If'the unloaded valves should close at the and of the piston stroke away from said valves due to the reduction of pressure be. low the power oftheir springs, they will be 85 toward the said valves and will remain open until the pressure in the auxiliary receivers .is reduced to a point below the power of said sprin s.

"When t e compressor is working with the auxiliary receiver valves closed, it will 'be seen that the auxiliary receivers remain full of fluid at maximum ressure, the valves preventing the fluid rom passing back-into the cylinder. It is to be understood that by the term re ulating device, I wish to include any mecfianical, electrical or fluid means whic can be employed for carrying outthe objects of my invention; hence I do notwish to limit myself to the ,particular re ulatmg -device herein shown and described, at What I' claim is: ,1 1. The combination with the cylinder of Rosa fluid com ressor, of auxiliary receivers therefor, an means for opening or closing '1 communication between the cylinder and its auxiliary receivers at successively attained pressures. f

The combination with the cylinder of a fluid compressor, of auxiliary receivers there- 'for, and fluid pressure controlled means for o enin or closing communication. between tie cy inder and its auxiliary receivers at successively attained pressures.

tion between the cylinder an opened again as soon as the piston starts 3. The combination with the cylinders. of aduplex single-Sta e fluid compressor,- .of auxiliary receivers t erefor, and meansfor opening or closing communication between the cylinders and their auxiliary receivers at successively attained pressures.

4. The combination with the cylindersofl a duplex single-Sta e fluid compressor, of

- auxiliary receivers t erefor, and fluid. pressure cont-rolled means for opening. or closing communication between the cylinders and their auxiliary receivers at successively attained pressures.

5. The combination. with the cylinder of a fluid 'compressor,'of auxiliary receivers therefor, and flu1d pressure cont-rolled valves for opening orclosin its auxiliary receivers at successively attained ressur'es. 6; The combination with the cy indersof .a duplex single-sta e fluid compressor, of

cominunica-,

auxiliary receivers t erefor, and fluid pres sure cont-rolled valves for opening or closing communication betweenthe cylinders and,their auxiliary receivers at successively attained pressures.-

7. The combination withthe cylinder of a fluid compressor of auxiliar receivers therefor, valves for opening or c osmgcommunication' between the cylinder and'its auxiliary receivers at successively attained pressures andunloading devices for the said,

valves. I 1

8. The combination with the cylinder of a fluid compressor, of auxiliary receivers therefor, valves for opening or closingicommunication between the cylinder "and itsv auxiliary receivers at successively attained pressures andfluid ressure controlled unloading devices. for t e said yalves.

9'. The combination with'the cylinders of a duplex single-stage fluid compressor, of.

auxil ary receivers therefor, .valves for opemn or closing -commun cationbet-ween the cyl nders and theirauxihary receivers at successively attained pressures. and unloading devil-es for the said valves.

10. The combination with the cylinders of a duplexsingle-stage fluid compressor, of auxiliary receivers therefor, valves for opening or closing communication between successively attained pressures and fluid ressure controlled unloading devices for he said valves. 4

11. In a fluid com ressor, the combination with" pum in'g mec anism, of means independent o the valves of the pumping mechanism for unloading it in successive 'well defined steps.

12. In a fluid compressor, the combination withpumping mechanism, of fluid pressure controlled means independent of the valves of the pumping. mechanism for unloading it in successive well defined steps.

the cylinders and theirauxiliary receivers atl 13: In a fluid compressor, the combina- 4 tion withpumping mechanism, of means independent of the valves of the' pumping mechanism for; loading 01- unloading it in successive well defined steps.

14:. In a fluid compressor, the combination with pumping mechanism, of fluid'pres- ,sure controlled means independent of the valves ofthe' umpingmechanism for loading'or unloa ing it in successive well defined'steps;

15.'In a fluid compressor, the combination with pumping mechanism, of unloading devices independent of the valves of the pumping mechanism fitted 'to operate at different successively attained pressures.

16: In afluid compressor, the combination with pumping" mechanism, of fluid pressure controlled unloading devices independent of the valves of the pumping mech anism' fitted to operate at difierent successively attained pressures.

17. In a duplex single-stage fluid compressor, the combination with pumping mechanism, of means independentot the valves of the pumping mechanism for unloading it in successive well defined steps.

18. In a duplex single-stage fluid compres'sor, the combination with pumping mechanism, of fluid pressure controlled means independent of the valves of the pumping mechanism for unloading it in successive well defined steps.

19. In. a duplex single-stage fluid 'com- 'pressor, the combination 'with pumping mechanism, of means independent of the valves of the pumping mechanism for: un loading or loading it in successive well defined steps.

20. In a duplex single-stage fluid compressor, the combinationwith pumping mechanism, of fluid pressure controlled means independent of the valves of the I pumping mechanism for unloading or loading it in successive well defined steps.

21. The combination with the cylinder of a fluid compressor, of auxiliary receivers, valves for opening and closing communication between the cylinder andthe auxiliary receivers and regulators connected to. the backs of the valves for successively unloading them, as difi'erent predetermined high g, t e

pressures are reached, for unload compressor step by step.

22. The comb'nation with the cylinder of. a fluid compressor, of auxiliary receivers,

valves for opening and closing communication between the cylinder and the 'auxlllary receivers and flllld pressure governed regulators connected to the backs of the valves for successively unloading them as different predetermined high pressures are reached, for-unloading the compressor step by step.

' 23. The combination with the cylinder of a fluid compressor, of auxiliary receivers,

valves for opening and closing commuhica 'tion between the cylinder and auxiliary re-.

ceivers and regulators for successively un-I loading the valves as the pressure'rises to predetermined points and for successively loading thevvalves as the pressure falls to,

predetermined points, for automatically un-- step.

a fiui d compressor, of auxiliary receivers,

valves for opening and closing communica tion between the cylinder and the auxiliary receivers and fluidpressure governed regulators for successively unloading the valves andfor successively loading the valves as the pressure falls to predetermined points,

for automatically unloading and loading the compressor step by step.

25. .The combination with the cylinders of afluid compressor, of auxiliary receivers, valves for opening and closing communication between' the cylinders and auxiliary receivers and regulators connected to the backs of the valves for successively unloading them tion between the cylinders and auxiliary re-' 24. The combination with the cylinder of loading and loading the compressor step by e6 as the pressure rises to predetermined points ceivcrs and regulators for successively unloading the valves as the pressure rises to predetermined high points and for successively loading the valves as the pressure falls to predetermined points, for automatically unloading and loading the compressor step by step.'-

28. The combination with the cylinders of a fluid compressor, of auxiliary receivers, valves for'opening and closin communication between the cylinders an auxiliary re:

ceivers and fluid pressuregoverned regu lators for successively unloading the. valves as the pressure rises to predetermined hi h points and for successively loadingt e 1 valves -as the pressure falls to predetermined points, for automatically unloading and loading the compressor step by step.

'29. In a variable volume fluid compressor, the combination with the fluid compressor cylinder and the receiver for the compressed fluid generated by said compressor, .of-- a plurality of compartments compressed and means for successively placing the compartments in communication with the clearance space in said cylinder as the pressure in the receiver rises to different predetermined points.

30. In a variable volume fluid. compressor, the combination with the fluid com pressor cylinder and the receiver for the compressed fluid pressor, of a plurality of compartments and means for successively placing the compartments in communication with the clearance space in said cylinder as the pressure in the receiver rises to different predetermined points and to successively close communication between the said compartlnent's'and clearance space in said cylinder as the pressure in the receiver falls to different predetermined points. a 31. In a variable volume fluid compressor, the combination with the fluid compressor cylinder and the receiver for the compressed fluid generated by said compressor, of a plurality of compartments and automatiomeans for successively placing the compartments .in communication with the clearance space in said cylinder as the pressure in the receiver rises to differ- 'ent predetermined points.

32. In a variable volume fluid compressor, the combination with the fluid compressor cylinder and the receiver for the compressed fluid generated by said com- --pressor, of a plurality of compartments and automatic 7 'means for successively placing the compartments in communication with the clearance space in said cylinder as the pressure in the receiver rises to difl'erent predetermined points and to successively close communication between the said compartments and clearance space in said cylinder as the pressure in the receiver falls to difl'erent predetermined points.

33. In a variable volume fluid compressor, the combination with the fluid compressor cylinder and the receiver for the fluid generated by said compressor, of a plurality of compartments and fluid pressure cont-rolled means for successively placing the compartments in communication with the clearance space in said cylinder as the pressure in the receiver rises to different predetermined points.

34. In a variable volume fluid compressor, the combination with the fluid compressor cylinder and the receiver for the compressed fluid generated by said compressor, of a plurality of compartments and fluid pressure controlled means for successively placing the compartments'in communication with the clearance space in said cylinder as the pressure in the receiver rises to diflerent predetermined points and to successively close communication between the said compartments and clearance space generated by said com-- automatic means in said cylinder as the pressure in the receiver falls to different predetermined points.

35. In a variable volume fluid compressor, the combination with fluid compressor cylinders and thereceiver for the compressed fluid generated by said compressor, of a plurality of compartments and means for successively placing the compartments in communication with the clearance spaces in said cylinders as the pressure in" the receiver rises. to different predetermined points.

36. In a variable --volum efluid com-- pressor, the combination with fluid compressor cylinders and the receiver for the compressed fluid generated by said compressor, .of a plurality of compartments and means for successivelyplacing the compartments in communication with the clearance spaces in said cylinders as the'pressure in the receiver rises to'difl'er'ent predetermined points and to successively clo'se commimication between the said compartments and the clearance spaces in'said cylinders as .the pressure in the-receiver falls to different predetermine: points.

37. In a pressor, the combination with' fluid compressor cylindersund the receiver for the compressed fluid generated by said .compressor, ofa plurality of compartments and for successively placing the compartments in communication with the clearance spaces in said cylinders as the pressure in the receiver rises to different predetermined points. v

38. In a variable volume fluid confipressor, the combination with fluid compressor cylinders and the receiver for the compressed fluid generated by said compressor, of a plurality of compartments and automatic means for successively placing the compartments in communication with the clearance spaces in said cylinders as the pressure in the receiver rises to different points and to successively close communication between the said compartments the clearance spaces in said cylinders as the pressure in the receiver falls to 'difl'erent predetermined oints.

39. In a varlable volume fluid compresv'ariable volume fluid comand sor, the combination with fluid compressor cylinders and the receiver for the compressed fluid generated by said compressor, of a plu rahty of compartments and fluid pressure controlled means for successively placing the v rality of compartments and fluid pressure controlled means for successively placing the compartments in communicatlon .with the clearanc'espacesgin said cylinders as the pressure in the-recelver rises to: different predetermined points and to successively close communication betweenthe said compartment s and the clearance spaces in said f means for placingone of saidcom'partments cylinders as the pressure in the receiver falls to difl'erent predetermined points. I I 41. In a variable volume fluid compresv sor, the combination with a fluid compressor cylinder and the receiver for the com ressed fluid generated by said compressor, 0 a plurality of compartments and automatic in communication with the-clearance space 'in-said cylinderwhen the pressure in said receivers reaches a predetermined point and for successively placing the rema nder of said compartments m communication with said; clearance space when the pressure 'in said receivers continues to rise.

42. In aflvariable-volume fluid compres sor,-the combination-with a fluid compressor cylinder and the receiverfor the com ressed 2' fluid; generated by said compressor, 0 a plu rality; of compartments and automatic means'forplacing'one of said compartments in communication with the clearance space insaid cylinder when the pressure in said' receivrsEreach'es a predetermined point and for successively placing the remainder of sa d compartments 1n commumcation with said clearance space when the pressure in saidreceivers continues to rise and for sucing it in successive well fluid pressure controlled means for unload-'1 ing it in successive well defined steps 45. In a fluid compressor, the combination with single acting pumpin mechanism,v of

means for loading or unloa ing it in succes sive well defined steps. a

46. In a fluid compressor, the combination with single acting pumping mechanism, of fluid pressure controlled means for loading or unloading it in successive well defined steps.

Intestimony, that claim the foregoing as my invention, I have signedmy name in presence of two witnesses, this 25th day of May,-1907.

- WILLIAM PRELLWITZ;

Witnesses: v

' F. GEORGE'BARRY,

HENRY THIEME. 

